A new radiative single-crystal diffractometer microfurnace incorporating MgO as a high-temperature cement and internal temperature calibrant

A new radiative microfurnace has been developed for high-temperature single-crystal work on the four-circle diffractometer. The microfurnace is fairly easy to construct and can be operated at temperatures up to 1270 K with a precision of ± 6 K. A calibrated shunt in the circuitry of the microfurnace is used to determine the microfurnace's resistance, current draw and power usage for any given temperature during a diffraction experiment. A procedure for mounting single crystals in a refractory cement that can be used as an internal calibrant of temperature is also described. The thermal expansion properties of periclase (MgO) have been reinvestigated.